Electrical problem with 98 Ford Expedition

My 98 Expedition starts and runs ok but after running a while no specific time at random different dash lights come on like door ajar, 4×4 low high on, the starter will engage while running then disengage off and on then it will stop running. It will start up again and start doing it again. It also drains battery overnight. Any suggestions on what is causing these problems?

My 98 Expedition starts and runs ok but after running a while no specific time at random different dash lights come on like door ajar, 4×4 low high on, the starter will engage while running then disengage off and on then it will stop running. It will start up again and start doing it again. It also drains battery overnight. Any suggestions on what is causing these problems?

With the starter engaging I would lean towards bad ignition switch.

Don't think it's ignition switch but not sure. Because while running different lights on the dash cluster start flashing on and off first, then the starter will engage then will stop, then more lights on the dash will flash, starter does it again it does this a few times then the engine will stop running. But will start back up run approximately a minute then it has same problem again. Ignition switch seems ok doesn't stick in start position. I think it's something electrical the interior light stays on when dash lights start flashing.

I would disconnect the battery, then in the passenger cab unbolt the fusebox to be able to move it away from the mount surface to see if there is any corrosion on the back side. There are known problems with water leaks getting into the back of the fusebox.

Somebody told me to replace the GEM module that's located above the fuse box. I went to the junk yard and got 2 of them and I noticed that there are different numbers on them. Can anyone tell me what is difference between different boxes and how to tell which box will be compatible with my Expedition? ? ? ?

The 98 only had the 5.4 liter available. 99 started to offer other engines. If you are absolutely sure they came from 98's, then I would try both. I don't have the translation for the numbers on the GEM's, but you could go to the expedition specific forum and ask there. Here is the link
http://www.expeditionforum.com/forums/1st-gen-1997-2002.42/